The use of pipette devices for the transfer and dispensing of precise quantities of fluids in analysis is well known. Likewise, disposable plastic tips used with pipetting devices have been commercially available for decades. These tips are used with pipetting devices that may use 1, 8, 12, or 96 tips simultaneously, and are usually packed vertically in a pipette tip rack.
The function of a pipette tip rack is to organize disposable pipette tips in a manner for convenient placement on a pipette. A pipette tip rack is usually a plastic box that has 96 holes into which the pipette tips are placed. The 96 holes are typically arranged in an eight by twelve array that are spaced 9 mm apart on their centerlines. Generally, such racks comprise a rigid base with vertical sides joined at contiguous edges and horizontally supporting a rigid pipette tip organizing tray having an array of pipette receiving holes extending through the top surface of the tray. Alternatively, pipette tip racks comprise a rigid tray which includes support sides and a flat top surface containing an array of holes for receiving and supporting an array of pipette tips. In either embodiment, the pipette tips are organized and held vertically by the array of holes for ease of access. Either a technician or a mechanical pipetting device simply places a pipette over the rack and lowers the distal end of the pipette into a proximal or upper end of a vertically oriented pipette tip and presses down to affix the tip which is held to the pipette by friction.
After all the tips are used the customary practice has been to either reload the rack by hand with pipette tips purchased in bulk or dispose of the rack. Presently, these two customary practices each present significant disadvantages. The disadvantage of reloading the tips into the rack by hand is that it is a very time consuming operation for lab workers who are generally over qualified for such repetitious work, as well as, the pipette tips may become contaminated by the manual handling. The disadvantage of disposing of the rack is that it ordinarily consists of three molded parts that still retain some value, namely, the rack, itself, a cover to enclose the tips, and a baseplate to enclose and seal the bottom of the rack. Since tips are often used in large quantities, disposing of bulky racks is wasteful and environmentally harmful. As a result, manufacturers are paying more attention to the issues that effect cost and storage space requirements, and the environment. This attention, in turn, has generated a desire to eliminate or reduce the amount of packaging required to ship and store products. These concerns have driven the need to develop a new design for a pipette tip rack.